The Role of Frozen Section Examination in Thyroid Surgery

In endocrine pathology, frozen section (FS) examination is most commonly used for the intraoperative evaluation of thyroid and parathyroid tumors, as well as cervical lymph nodes. In the past, frozen section was considered a fundamental tool in thyroid surgery. However, with advancements in preoperative ultrasound and fine-needle aspiration biopsy (FNAB), there have been increasing queries about its routine use due to the improved preoperative diagnosis. Nowadays, while the use of FS during thyroidectomy has decreased, it is still used as an additional method for different purposes intraoperatively. FS may not always provide definitive results. If FS will alter the surgical plan or extent, it should be applied. Routine FS is not recommended for evaluating thyroid nodules. But in addition to FNAB, if FS results may change the operation plan or extent, they can be utilized. FS should not be applied for thyroid lesions smaller than 1 cm, and the entire lesion should not be frozen for FS. For the assessment of thyroid nodules, the use of FS is recommended based on the Bethesda categories of FNAB. In Bethesda I category nodules, FS may contribute to distinguishing between malignant and benign lesions and guide surgical treatment. In Bethesda II nodules, where the malignancy rate is low, the performance of FNAB and FS can be compared, but it's not recommended due to the lack of a significant contribution to the surgical strategy. The sensitivity of FS in Bethesda III and IV nodules is low; its contribution to the diagnosis is limited, and it does not provide an apparent benefit to treatment; therefore, it is not recommended. In Bethesda V nodules, FS can effectively confirm the malignancy diagnosis, contribute to the surgical strategy, and reduce the possibility of completion thyroidectomy, and accordingly, it is recommended for use. Nonetheless, in Bethesda V nodules with a benign FS report, the malignancy rate remains high, so it should not be used to rule out malignancy. In Bethesda VI nodules, the performance of FS is lower or comparable to FNAB and does not significantly contribute to the treatment strategy; hence, it is not recommended. Particularly in patients with papillary thyroid cancer, intraoperative FS can be effective in detecting extrathyroidal extension and can assist the surgeon in determining the extent of thyroid surgery and central neck dissection. FS has high sensitivity and specificity in evaluating the lymphatic status of the central region intraoperatively and can be used to determine the extent of central compartment node dissection. During thyroidectomy, FS examination can be used in recognizing parathyroid tissue and distinguishing it from fatty tissue, thymus, thyroid, lymph nodes, especially in differentiating metastatic lymph nodes.

Tiroid Cerrahisinde Frozen Kesit Ýncelemenin Yeri

Endokrin patolojide frozen kesit (FS) inceleme en sýk tiroid ve paratiroid tümörleri ve servikal lenf nodlarýnýn intraoperatif deðerlendirilmesinde kullanýlmaktadýr. Geçmiþte tiroid cerrahisinde frozen inceleme temel araç olarak deðerlendirilmekteydi. Preoperatif utrasonografi ve ince iðne aspirasyon biyopsisi (FNAB)’ndeki geliþmelere baðlý olarak preoperatif tanýnýn artmasý ile son zamanlarda rutin kullanýmý ile ilgili sorgulamalar artmaktadýr. Günümüzde tiroidektomi sýrasýnda FS kullanýmý azal-makla birlikte halen farklý amaçlarla intraoperatif ek yöntem olarak kullanýlmaktadýr. FS her zaman kesin sonuç vermeyebilir. FS operasyon planýný ve geniþliðini deðiþtirecekse uygulanmalýdýr. Tiroid nodüllerinin deðerlendirilmesinde rutin FS önerilmemektedir. Eðer FNAB ek olarak FS sonuçlarý operasyon planýný veya operasyon geniþliðini deðiþtirecekse kullanýlabilir. FS 1 cm’den küçük tiroid lezyonlarýnda uygulanmamalýdýr ve bir lezyonun tümü FS için dondurulmamalýdýr. Tiroid nodülle-rinde FNAB Bethesda kategorilerine göre FS kullanýmýna karar verilebilir. FS Bethesda I kategori nodüllerin malign benign ayrýmýna ve cerrahi tedavisinde katký saðlayabilir. Bethesda II nodüllerde mlignite oraný düþük olup FNAB ile FS performansý karþýlatýrýlabilir olup, cerrahi startejiye anlamlý katkýsý olmadýðýndan önerilmemektedir. Bethesda III ve IV nodüllerde FS’nin sensitivitesi düþük, tanýya katkýsý sýnýrlý olup, tedaviye anlamlý katký saðlamadýðý için önerilmemektedir. Bethesda V no-düllerde FS nodüllerin malignite tanýsýný doðrulamada etkili olup, cerrahi stratejiye anlamlý katký sað-layarak tamamlayýcý tiroidektomi olasýlýðýný azaltabilir ve kullanýlmasý önerilmektedir. Bethesda V nodüllerde FS benign rapor edilen nodüllerde malignite oraný yüksek olup, maligniteyi dýþlamada kullanýlmamalýdýr. Bethesda VI nodüllerde FS’nin performansý FNAB’den düþük veya karþýlaþtýrýla-bilir ve tedavi stratejisine anlamlý katký saðlamayacaðý için kullanýlmasý önerilmemektedir. Özellikle papiller tiroid kanserli hastalarda intraoperatif FS’ýn ekstratiroidal yayýlýmý saptamada etkili olup, ti-roid cerrahisinin geniþliði ve santral diseksiyon geniþliði konusunda cerraha yardýmcý olabilir. FS santral bölgenin lenfatik durumunun intraoperatif olarak deðerlendirilmesinde yüksek duyarlýlýk ve özgüllüðe sahip yararlý bir araç olup, santral bölge nod diseksiyonu geniþliðini belirlemede kullaný-labilir. Tiroidektomi sýrasýnda FS inceleme paratiroid dokusunun tanýnmasýnda ve yað dokusu, timüs, tiroid, lenf nodu özellikle de metastatik lenf nodundan ayrýmýnda kullanýlabilir. (SETB-2023-12-239)